Preparation of phenol or phenol derivatives

ABSTRACT

The invention relates to a process for the production of phenol or phenol derivatives by oxidation of the aromatic nucleus of benzene or benzene derivatives with nitrous oxide over a zeolite catalyst.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to organic synthesis and, moreparticularly, to processes for preparing phenol or derivatives.

2. Description of the Prior Art

Oxygen-containing benzene derivatives such as phenol, dihydric phenols,benzoquinone, chlorophenols, cresols, ethylphenols, nitrophenols and thelike are valuable products and find an extensive use for variousapplications. The most mass-scale prepared product of this class isphenol, the basic amount of which is intended for the production ofphenolic resins, synthesis of adipic acid, caprolactam, bisphenol,nitro- and chlorophenols, phenol sulphonic acids and the like. Dihydricphenols are employed in photography, as well as antioxidants andmodifying agents for stabilization plastics. Cresols are used for theproduction of cresol-formaldehyde resins; chlorophenols for themanufacture of herbicides; benzoquinone as a raw material for thepreparation of hydroquinone and the like.

Known in the art is a principal possibility for preparingoxygen-containing benzene derivatives by way of a direct oxidation ofbenzene and derivatives thereof. However, all the attempts to carry outthese reactions with an acceptable selectivity repeatedly undertakenduring recent decades has proved to be unsuccessful. For example, themain products of oxidation of benzene with molecular oxygen, dependingon conditions, are either maleic anhydride (on specially selectedcatalysts) or products of a complete oxidation, whereas phenol andbenzoquinone are formed but in trace amounts. In a direct oxidation ofbenzene derivatives, such as toluene, the oxidation process affects thefunctional group in the first place with the formation of benzaldehydeand benzoic acid, but the formation of cresols is not observed (G. I.Golodetz. Heterogeneous-Catalytic Oxidation of Organic Compounds. Kiev,"Naukova Dumka" Publishing House, 1978, pp. 209-224).

There are a number of processes for the production of oxygen-containingbenzene derivatives (L. Tedder, A. Nechvatal, A. Jubb. IndustrialOrganic Chemistry, Moscow, "MIR" Publishers 1977, pp. 198-205). In thepreparation of phenol, the most widely used is the so-called cumeneprocess accounting for more than 90% of the world output of phenol (J.Econ. and Eng. Review, 1982, vol. 14, No. 5, p. 47). This processconsists of three stages:

alkylation of benzene with propylene to give cumene (isopropylbenzene);

oxidation of cumene to cumene hydroperoxide;

decomposition of cumene hydroperoxide with the formation of phenol andequimolar amounts of acetone.

This is a multi-stage process, and its efficiency depends to a greatextent on the possibility for commercialization of acetone. However,recently there has been a declining trend in the demand for acetonewhich in the foreseeable future may result in the necessity ofabandoning the cumene process (Kohn P. M., Bolton L., Cottrell R.,McQueen S., Ushio S., Chem. Eng. (USA), 1979, vol. 86, No. 8, pp.62-64).

Known in the art is a process for preparing phenol (Iwamoto M. HirataJ., Matsukami K., Kagawa S., J. Phys. Chem., 1983, vol. 87, No. 6, pp.903-905) by way of oxidation of benzene with nitrous oxide at atemperature of 550° C.-600° C.:

    C.sub.6 H.sub.6 +N.sub.2 O=C.sub.6 H.sub.5 OH+N.sub.2

In this case as the catalyst use is made of vanadium oxide, molybdenumoxide and tungsten oxide. To improve selectivity water vapors are addedto the reaction mixture. The best results were obtained on a catalyst3.3% V₂ O₅ /SiO₂ at the temperature of 550° C. at the followingcomposition of the reaction mixture: 8.2% benzene, 16.9% nitrogen oxideand 30.7% water. Conversion of benzene under these conditions, X, was10.7%, selectivity, S, gas 71.5% which corresponded to a yield, Y, ofphenol of 7.7% (Y=X.S).

However, this process features an insufficient yield of phenol; theprocess requires a high temperature and introduction of water into thereaction mixture which necessitates additional power consumption for itsevaporation and complicates isolation of the desired product. Thisprocess was not practiced on a commercial scale. This was apparentlyassociated with an insufficient selectivity as well. The selectivityparameter is of a great importance for this reaction, since lowering ofselectivity due to over oxidation means not only an increased benzeneconsumption, but especially high consumption of nitrous oxide.

To prepare more complex oxygen-containing benzene derivatives, twopossibilities can be used. The first envisages introduction of arequired functional group into the respective oxygen-containing benzenederivative; the second resides in a direct oxidation of the respectivebenzene derivative. The difficulties of carrying out the lesscomplicated reaction of preparation of phenol from benzene would be alsoencountered in the production of other oxygen-containing benzenederivatives. But in this case, the problem of selectiveness is stillmore acute and, hence, that of the process efficiency, since the numberof possible directions of the reaction (o-, p- and m-isomers,participation of functional groups in the chemical transformation)considerably increases.

For example, the process for preparing dihydric phenols is known whichis effected in a manner similar to that of the cumene process for thepreparation of phenol and which features a multi-stage character and thenecessity of commercialization of acetone formed in large quantities(Vorozhtsov N. N. Foundations fo Synthesis of Intermediate Products andDyestuffs. M., Goskhimizdat Publishers, 1955, p. 621). In this process,alkylation of benzene with propylene is effected in the first stage withpropylene; in so doing, there is possible the formation of three isomersof diisopropyl and triisopropylbenzene. Then, the correspondingderivatives of diisopropylbenzene are oxidized into cumenehydroperoxides and, finally, decomposition of cumene dihydroperoxide iseffected in the last stage of the process.

There is a number of processes for the preparation of dihydric phenols,as well as chlorophenols and phenolsulphonic acids based on an alkalitreatment of corresponding chloro- and sulpho-benzene derivatives. Theseprocesses, however, necessitate the use of aggressivereagents--concentrated acids and alkalis and are accompanied by theformation of several tons of alkaline and acidic effluents per ton ofthe product, thus complicating the problem of the environment pollution.

Known in the art is another process for the preparation ofoxygen-containing benzene derivatives, in particular phenol andchlorophenol (Suzuki E., Nakashiro K., Onoy Y., Chemistry Letters, 1988,No. 6, pp. 953-956). In this process, benzene or chlorobenzene in thevapor phase are subjected to oxidation with nitrous oxide on apentasil-type catalyst of an alumosilicate composition with the ratio ofSiO₂ /Al₂ O₃ =85 at the temperature of 330° C. with the followingcomposition of the reaction mixture: 6.9 mol. % benzene, 51 mol. %nitrous oxide, nitrogen being the balance. The time of contact of thegas mixture with the catalyst is 2 seconds. The yield of phenol in thiscase is 5.5%. Under similar conditions (temperature 330° C., 3.9%chlorobenzene, 71% nitrous oxide, the contact time--2 seconds) in theoxidation of chlorobenzene, yields of chlorophenol did not exceed 6.7%.The use of an alumosilicate catalyst as compared to the above-mentionedvanadium catalyst (Iwamoto M., Hirata J., Matsukami K., Kagawa S., J.Phys. Chem. 1983, vol. 87, No. 6, pp. 903-905) made it possible tosubstantially simplify the process by carrying out the same withoutintroduction of water vapors into the reaction mixture. However, yieldsof phenol and chlorophenol in this process remained low, 5.5% and 6.7%respectively.

Known in the art is another process for phenol preparation (Gubelmann,et al. EP 341,165 and U.S. Pat. No. 5,001,280) by way of benzeneoxidation with nitrous oxide. Like Suzuki, et al., Gubelmann, et al.make use of zeolite catalysts of aluminosilicate composition but of agreater SiO₂ /Al₂ O₃ ratio ranging from 90 to 500. Higher phenol yieldsup to 16% at 400° C. are shown but, nevertheless, such yields are notsufficiently high.

It is an object of the present invention to provide such a process forpreparing oxygen-containing benzene derivatives which would make itpossible to obtain the desired products in a sufficiently high yieldfollowing a simple procedure.

SUMMARY OF THE INVENTION

This object is accomplished by the process for preparing phenol orderivatives by way of oxidation of aromatic nucleus of benzene orderivative thereof with nitrous oxide at an elevated temperature in thepresence of a zeolite catalyst.

DETAILED DESCRIPTION

According to the present invention, the oxidation of benzene orderivatives thereof is effected at a temperature within the range of275° C. to 450° C., a time of contact of the reaction mixture with thecatalyst of not more than 8 seconds and using, as the catalyst, azeolite of the composition y.El₂ O_(n).x.Fe₂ O₃.SiO₂, wherein y=0-6.5.10⁻², x=1.5.10⁻⁵ -2. 10⁻², El at least one of elements of 2, 3, 4, 5Periods of the periodic system; n is valence of the element.

At y=0 the catalyst has an iron-silicate composition x.Fe₂ O₃.SiO₂. Theuse of iron-silicates as catalysts of partial oxidation is unknown inthe literature and is not obvious, since none of the components of theprincipal composition (Fe₂ O₃, SiO₂) is a catalyst of reactions of thistype.

The incorporation, into the catalyst, of elements of Periods 2, 3, 4 and5 of the periodic system changes its properties. Thus, zeolitesincorporating aluminum are more active, all other conditions beingequal. With an increasing content of sodium, the catalyst activity islowered. If an iron silicate additionally incorporates more than oneelement, "y" is the total of molar coefficients of corresponding oxidesof the elements introduced additionally into the zeolite. For example,if the catalysts composition corresponds to the formula:

1.1.10⁻².CaO.4.2.10⁻³ MgO.10⁻².Al₂ O₃.3.4.10⁻³.Fe₂ O₃.SiO₂, than"y"=1.1.10⁻² +4.2.10⁻³ +10⁻² =2.52.10⁻² and the sum of molar coefficientcannot exceed 6.5.10⁻².

As the catalysts use is made of high-silica zeolites of variousstructural types: pentasils (ZSM-5, ZSM-11, ZSM-12, ZSM-23), mordenites,BETA, EU-1.

Only the use of zeolite catalysts of the above-mentioned composition andof a process temperature within the range of 275° C. to 450° C. makes itpossible to accomplish the object of the present invention: to increasethe yield of the desired product, e.g. phenol, up to 38%.

It is a strictly observed optimal composition of the catalyst thatensures its catalytic properties. A lowered or an increased content ofcorresponding components beyond the limits of the above-specified rangeresults in a reduced yield of the desired product either due to adecreased conversion of benzene or a derivative thereof, or due to animpaired selectivity of the process. For the same reason, it isinexpedient to use an elevated or a lowered temperature. The change ofthe molar ratio C_(C6) H₆ /C_(N2) O does not substantially affect yieldsof the desired product; with an increase of this ratio the degree ofconversion of the starting components increases, but selectivity (forthe desired product) is lowered. For this reason, from this standpoint amixture of the stoichiometric composition is the most preferable.Extension of the contact time over 8 seconds is inexpedient, sinceyields of the desired products change in this case but insignificantly.

The catalyst can be used with or without a binder; as the latter, usecan be made of an additive of Al₂ O₃, SiO₂ or a mixture of both. The useof a binder makes it possible to obtain stronger catalysts of adifferent shape (granules, rings and the like).

The process of oxidation of benzene or derivatives thereof is anexothermal reaction. Hence, it is advisable to use an inert gas whichlowers the thermal load on the catalyst. This makes it possible to avoidcatalyst overheating and contributes to elevation of the reactionselectivity in respect of the desired products.

The process for preparing oxygen-containing benzene derivatives issimple and can be effected in the following manner.

The process for producing the catalyst is conventional and consists inthe following (Ione K. G., Vostrikova L. A., Uspekhi Khimii, 1987, vol.LVI, iss. 3, pp. 393-427). A mixture consisting of a source of silicon,a source of iron and, when necessary, a source of El^(n+), an alkali,organic surfactants and, in some cases, a crystallization seed, ishomogenized and then placed into an autoclave, wherein underhydrothermal conditions it is kept for 1 to 30 days at a temperaturewithin the range of from 80° C. to 200° C. On completion ofcrystallization, the residue is filtered off, washed with distilledwater and dried. Prior to catalytic tests, the solid product is calcinedat a temperature within the range of from 520° C. to 550° C. for theremoval of organic inclusions and, if required, decationization isconducted using solutions of NH₄ OH+NH₄ Cl or solutions of inorganicacids. In some cases a required element is introduced into theiron-silicate matrix using ion-exchange methods (Ione K. G.Polyfunctional Catalysis on Zeolites. Novosibirsk, "Nauka" Publishers,1982, pp. 97-137) or impregnation (Dzisko V. A. Foundations of Methodsfor Preparation of Catalysts. Novosibirsk, "Nauka" Publishers, 1983, pp.148-161).

The catalyst is charged into a reactor with an inside diameter of 7 mm.The catalyst volume is 2 cm³, particle size is 0.5-1 mm. The catalyst isheated to the predetermined temperature, and the reaction mixture,benzene or a derivative thereof, nitrogen oxide and, when required,helium or any other inert gas, is introduced at an appropriate rate.After contact with the catalyst, the mixture is subjected tocondensation. The desired products are isolated by conventionaltechniques such as by rectification.

The mixture composition before and after reaction is determined by wayof a chromatographic analysis, and from the obtained data, the degree ofconversion of benzene or of the derivative thereof is calculated by theformula:

    X=(C.sub.i -C.sub.o)/C.sub.i,

wherein:

X is degree of conversion of benzene or its derivative, %; C_(i) is thebenzene concentration (or concentration of its derivative) at the inletof the reactor, mol. %;

C_(o) is the concentration of benzene or its derivative at the outlet ofthe reactor, mol. %;

Selectivity with respect to the desired product is calculated by theformula:

    S=C.sub.p /(C.sub.i -C.sub.o),

wherein

S is the selectivity with respect to the desired product, %;

C_(i) is the concentration of benzene or a derivative thereof at theinlet of the reactor, mol. %;

C_(o) is the concentration of benzene or its derivative at the outlet ofthe reactor, mol. %;

C_(p) is the concentration of the desired product of the reaction, mol.%.

Yields of the desired product are calculated by the formula:

    Y=X.S/100,

wherein:

X--conversion of benzene or its derivative, %

S--selectivity with respect to the desired product, %.

Given hereinafter are characteristics averaged for three hours ofoperation of the catalyst.

After the stage of oxidation of benzene or a derivative thereof, thecatalyst is regenerated with oxygen or air, or with nitrogen oxide at atemperature within the range of from 400° C. to 550° C. and again usedfor oxidation of benzene or its derivative. Properties of the catalystin the reaction of oxidation remain unchanged after more than 20 cyclesof its regeneration.

The process for preparing phenol or phenol derivatives, as compared tothe known ones, ensures increased yields of the desired products, up to37%, which is considerably higher than the corresponding parameter inthe prior art process obtained under similar conditions (Suzuki, E.,Nakeshiro K., Ono Y. Chemistry Letters, 1988, No. 6, pp. 953-956). Theprocess features a simple procedure, is effected in a single stage andnecessitates no use of aggressive reagents. Furthermore, the processaccording to the present invention makes it possible to obtain a wholenumber of oxygen-containing benzene derivatives such as phenol,benzoquinone, dihydric phenols, cresols, chlorophenols and the like.

For a better understanding of the present invention, some specificexamples are given hereinbelow by way of illustration.

EXAMPLE 1

A synthetic zeolite of the composition 8.2.10⁻³.Fe₂ O₃. SiO₂ with thestructure ZSM-5 in the amount of 2 cm³ was charged into a reactor,heated to the temperature of 350° C. and a reaction mixture of thecomposition: 5 mol. % benzene, 20 mol. % nitrous oxide, the balance,helium, was fed thereinto at the rate of 1 cm³ /sec. The reactionmixture composition was discontinuously (once every 15 minutes) analyzedby means of a chromatograph. Apart from phenol and carbon dioxide, noother carbon-containing compounds were detected in the reactionproducts. The process had the following parameters:

    ______________________________________                                        conversion of benzene, X                                                                         15.4%                                                      selectivity for phenol, S                                                                        99.0%                                                      yield of phenol, Y 15.3%                                                      ______________________________________                                    

EXAMPLES 2-15

Phenol was obtained as in Example 1, except that temperature was variedas was the time of contact of the reaction mixture with the catalyst,wherefor at the same space velocity (1 cm³ /sec) the catalyst charge waschanged from 2 to 8 cm³. The catalyst characteristics, its temperature,the time of contact of the reaction mixture with the catalyst and thetest results are shown in Table 1 hereinbelow.

EXAMPLE 16

Phenol was prepared in a manner similar to that described in Example 1hereinbefore, except that the reaction mixture had the followingcomposition: 5 mol. % benzene, and 95 mol. % nitrous oxide.

The process parameters were as follows:

    ______________________________________                                        conversion of benzene, X                                                                         18.0%                                                      selectivity for phenol, S                                                                        83.5%                                                      yield of phenol, Y 15.0%                                                      ______________________________________                                    

                  TABLE 1                                                         ______________________________________                                        Effect of the Contact Time and Temperature on the Parameters                  of the Process of Oxidation of Benzene into Phenol on the                     Catalyst of the Composition 8.2 10.sup.-3 Fe.sub.2 O.sub.3 SiO.sub.2 with     the                                                                           Structure ZSM-5 (Composition of the Starting Feed: Benzene-                   5 mol. %, Nitrogen Oxide-20 mol %).                                           Averaged Characteristics for 3 Hours' Operation                                               Conversion Selectivity                                                                            Yield of                                  Example         of C.sub.6 H.sub.6                                                                       for C.sub.6 H.sub.5 OH                                                                 C.sub.6 H.sub.5 OH                        No.     T, °C.                                                                         X, %       S, %     Y, %                                      ______________________________________                                        Contact Time 1 sec.                                                           2       375     10.3       98.0      9.2                                      Contact Time 2 sec.                                                           3       300      8.4       100.0     8.4                                      4       375     22.4       94.3     21.0                                      5       400     28.9       88.0     25.4                                      6       420     35.5       71.0     25.3                                      Contact Time 4 sec.                                                           7       275     13.7       100.0    13.7                                      8       300     17.8       99.7     17.7                                      9       325     23.5       97.5     22.9                                      10      350     30.8       93.4     28.8                                      11      400     46.3       55.8     25.3                                      Contact Time 8 sec.                                                           12      275     14.2       100.0    14.2                                      13      300     22.1       98.0     21.7                                      14      325     31.4       96.1     30.2                                      15      350     39.0       90.4     35.3                                      ______________________________________                                    

EXAMPLES 17-82

Phenol was prepared as in Example 1 hereinbefore, except that variedwere chemical compositions of the catalysts, their structure and thereaction temperature. Characteristics of the catalysts, temperature ofthe reaction nd the results of tests are shown in Table 2 hereinbelow.

EXAMPLE 83

Phenol was produced in a manner similar to that described in Example 1hereinbefore, except that use was made of a catalyst having thecomposition of 8.4.10⁻³.Fe₂ O₃.SiO₂ containing, as the binder, 20% bymass of Al₂ O₃.

The process parameters were as follows:

    ______________________________________                                        conversion of benzene, X                                                                         32.0%                                                      selectivity for phenol, S                                                                        97.2%                                                      yield of phenol, Y  31.2%.                                                    ______________________________________                                    

EXAMPLE 84

Phenol was obtained as described in Example 1 hereinbefore, except thatuse was made of a catalyst of the composition of 8.4.10⁻³.Fe₂ O₃.SiO₂containing, as the binder, 25% by mass of SiO₂.

The process had the following parameters:

    ______________________________________                                        conversion of benzene, X                                                                         27.7%                                                      selectivity for phenol, S                                                                        96.8%                                                      yield of phenol, Y  26.8%.                                                    ______________________________________                                    

EXAMPLE 84

Phenol was prepared in a manner similar to that described in Example 1hereinbefore, except that use was made of a catalyst of the compositionof 8.4.10⁻³.Fe₂ O₃.SiO₂ containing, as the binder, 1% by mass of SiO₂.

The process had the following parameters:

    ______________________________________                                        conversion of benzene, X                                                                         29.2%                                                      selectivity for phenol, S                                                                        97.0%                                                      yield of phenol, Y 28.3%                                                      ______________________________________                                    

                                      TABLE 2                                     __________________________________________________________________________                                 Averaged                                              Catalyst                parameters for                                   Example                                                                            composition             3 hours of operation                             No.  molar ratio   Structure                                                                           T, °C.                                                                     X, %                                                                             S, %                                                                              Y, %                                      __________________________________________________________________________    17   2.0 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 500  2.0                                                                             100.0                                                                              2.0                                      18   2.0 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 425 25.5                                                                             94.0                                                                              24.0                                      19   4.9 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 350 22.6                                                                             82.6                                                                              18.7                                      20   9.4 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 400 29.5                                                                             81.5                                                                              24.0                                      21   2.0 · 10.sup.-2.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 330 28.6                                                                             91.0                                                                              26.0                                      22   2.0 · 10.sup.-2.Fe.sub.2 O.sub.3.SiO.sub.2                                         ZSM-5 350 47.0                                                                             78.7                                                                              37.6                                      23   1.2 · 10.sup.-3.Al.sub.2 O.sub.3.                                                  ZSM-5 500  2.0                                                                             100.0                                                                              2.0                                           3 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub. 2                       24   3.8 · 10.sup.-3.Al.sub.2 O.sub.3.                                                  ZSM-5 450  5.5                                                                             100.0                                                                              5.5                                           3 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                        25   3.8 · 10.sup.-3.Al.sub.2 O.sub.3.                                                  ZSM-5 500  7.9                                                                             82.0                                                                               6.3                                           3 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                        26   2.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  ZSM-5 330  6.3                                                                             100.0                                                                              6.3                                           1.6 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      27   2.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  ZSM-5 350  9.2                                                                             97.0                                                                               9.0                                           1.6 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      28   2.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  ZSM-5 375 14.5                                                                             72.0                                                                              10.5                                           1.6 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      29   2.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  ZSM-5 400 24.7                                                                             37.0                                                                               9.2                                           1.6 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      30   10.sup.-2.Al.sub.2 O.sub.3 .                                                                ZSM-5 330 10.0                                                                             97.0                                                                               9.7                                           2.8 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      31   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 350 13.0                                                                             92.0                                                                              11.9                                           2.8 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      32   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 375 17.0                                                                             70.5                                                                              12.0                                           2.8 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      33   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 400 32.0                                                                             33.0                                                                              10.5                                           2.8 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      34   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 375 28.0                                                                             50.0                                                                              14.0                                           1.9 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      35   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 300  8.4                                                                             100.0                                                                              8.4                                           1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      36   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 325 15.0                                                                             100.0                                                                             15.0                                           1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      37   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 350 18.0                                                                             99.0                                                                              17.3                                           1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      38   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 375 20.9                                                                             96.0                                                                              20.0                                           1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      39   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 500 31.0                                                                             10.0                                                                               3.1                                           1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      40   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 350  4.9                                                                             100.0                                                                              4.9                                           2.8 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      41   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 330 11.0                                                                             100.0                                                                             11.0                                           2.8 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      42   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 400 20.4                                                                             98.0                                                                              20.0                                           2.8 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      43   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 425 20.7                                                                             94.0                                                                              19.5                                           2.8 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      44   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 350  2.2                                                                             100.0                                                                              2.2                                           1.5 ·  10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                     45   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 400  9.7                                                                             100.0                                                                              9.7                                           1.5 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      46   10.sup.-2.Al.sub.2 O.sub.3.                                                                 ZSM-5 450 11.6                                                                             100.0                                                                             11.6                                           1.5 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      47   1.1 · 10.sup.-2.TiO.sub.2.                                                         ZSM-5 450  7.6                                                                             96.0                                                                               7.3                                           5.8 · 10.sup.-4.Fe.sub.2 O.sub.3.7.5 ·                      10.sup.-3.Al.sub.2 O.sub.3.SiO.sub.2                                     48   2.0 · 10.sup.-2.TiO.sub.2.                                                         ZSM-5 375 16.0                                                                             98.0                                                                              15.7                                           2.0 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      49   1.1 · 10.sup.-2.Na.sub.2 O.                                                        ZSM-5 400 11.8                                                                             95.0                                                                              11.2                                           8.4 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      50   1.1 · 10.sup.-2.Na.sub.2 O.                                                        ZSM-5 350  4.3                                                                             100.0                                                                              4.3                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     51   1.1 · 10.sup.-2.Na.sub.2 O.                                                        ZSM-5 400 12.6                                                                             100.0                                                                             12.6                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     52   7.9 · 10.sup.-3.Na.sub.2 O.                                                        ZSM-5 350  7.4                                                                             100.0                                                                              7.4                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     53   7.9 · 10.sup.-3.Na.sub.2 O.                                                        ZSM-5 400 19.9                                                                             98.0                                                                              19.5                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     54   6.0 · 10.sup.-4 Na.sub.2 O.                                                        ZSM-5 350 15.4                                                                             100.0                                                                             15.4                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     55   6.0 · 10.sup.-4 Na.sub.2 O.                                                        ZSM-5 400 23.4                                                                             97.6                                                                              22.9                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                                     56   10.sup.-2.ZnO.10.sup.-2.Al.sub.2 O.sub.3.                                                   ZSM-5 400 10.0                                                                             80.0                                                                               8.0                                           10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                     57   1.8 · 10.sup.-4.Co.sub.2 O.sub.3.                                                  ZSM-5 375 10.1                                                                             100.0                                                                             10.1                                           10.sup.-2.Al.sub.2 O.sub.3.                                                   3.4 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      58   1.8 · 10.sup.-4.Co.sub.2 O.sub.3.                                                  ZSM-5 400 11.7                                                                             100.0                                                                             11.7                                           10.sup.-2.Al.sub.2 O.sub.3.                                                   3.4 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      59   1.8 · 10.sup.-4.Co.sub.2 O.sub.3.                                                  ZSM-5 425 15.4                                                                             100.0                                                                             15.4                                           10.sup.-2.Al.sub.2 O.sub.3.3.4 ·                                     10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                                     60   1.8 · 10.sup.-4.Co.sub.2 O.sub.3.                                                  ZSM-5 450 18.7                                                                             99.4                                                                              18.6                                           10.sup.-2.Al.sub.2 O.sub.3.                                                   3.4 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      61   4.4 · 10.sup.-4.Co.sub.2 O.sub.3.                                                  ZSM-5 450  9.4                                                                             100.0                                                                              9.4                                           10.sup.-2.Al.sub.2 O.sub.3.1.5 ·                                     10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                                     62   1.2 · 10.sup.-4.V.sub.2 O.sub.3.                                                   ZSM-5 400  8.4                                                                             100.0                                                                              8.4                                           7.6 · 10.sup.-3.Al.sub.2 O.sub.3.                                    4.2 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      63   1.2 · 10.sup.-4.V.sub.2 O.sub.3.                                                   ZSM-5 450  9.8                                                                             99.8                                                                               9.8                                           7.6 · 10.sup.-3.Al.sub.2 O.sub.3.                                    4.2 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      64   10.sup.-4.Cr.sub.2 O.sub.3.                                                                 ZSM-5 450  9.0                                                                             99.0                                                                               8.9                                           10.sup.-2.Al.sub.2 O.sub.3.                                                   2.0 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      65   3.0 · 10.sup.-4.Mn.sub.2 O.sub.3.                                                  ZSM-5 425  8.5                                                                             98.3                                                                               8.3                                           10.sup.-2.Al.sub.2 O.sub.3.                                                   6.0 · 10.sup.-5.Fe.sub.2 O.sub.3.SiO.sub.2                      66   4.0 · 10.sup.-4 NiO.                                                               ZSM-5 425 10.0                                                                             99.0                                                                               9.7                                           10.sup.- 2.Al.sub.2 O.sub.3.2.7 ·                                    10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                     67   7.1 · 10.sup.-4 Mo.sub.2 O.sub.3.                                                  ZSM-5 425 12.0                                                                             99.0                                                                              11.9                                           10.sup.-2.Al.sub.2 O.sub.3.3.0 ·                                     10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                     68   7.1 · 10.sup.-3.B.sub.2 O.sub.3.                                                   ZSM-5 350 14.8                                                                             99.0                                                                              14.8                                           10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                     69   5.0 · 10.sup.-4.Na.sub.2 O.                                                        ZSM-5 350  6.0                                                                             100.0                                                                              6.0                                           9.0 · 10.sup.-3.Al.sub.2 O.sub.3.                                    4.0 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      70   5.0 · 10.sup.-4.Na.sub.2 O.                                                        ZSM-5 400 10.0                                                                             100.0                                                                             10.0                                           9.0 · 10.sup.-3.Al.sub.2 O.sub.3.                                    4.0 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      71   1.1 · 10.sup.-2.CaO.                                                               ZSM-11                                                                              350  4.1                                                                             100.0                                                                              4.0                                           4.2 · 10.sup.-3.MgO.10.sup.-2.Al.sub.2 O.sub.3.                      3.4 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      72   1.1 · 10.sup.-2.CaO.                                                               ZSM-11                                                                              400  7.7                                                                             100.0                                                                              7.7                                           4.2 · 10.sup.-3.MgO.10.sup.-2.Al.sub.2 O.sub.3.                      3.4 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      73   1.1 · 10.sup.-2.CaO.                                                               ZSM-11                                                                              425  9.9                                                                             98.0                                                                               9.4                                           4.2 · 10.sup.-3.MgO.10.sup.-2.Al.sub.2 O.sub.3.                      3.4 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      74   5.0 · 10.sup.-3.Al.sub.2 O.sub.3.                                                  ZSM-12                                                                              350  8.0                                                                             100.0                                                                              8.0                                           3.5 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      75   5.0 · 10.sup.-3.Al.sub.2 O.sub.3.                                                  ZSM-12                                                                              400 15.3                                                                             97.0                                                                              14.8                                           3.5 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      76   6.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  mordenite                                                                           350  7.2                                                                             100.0                                                                              7.2                                           5.4 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      77   6.5 · 10.sup.- 2.Al.sub.2 O.sub.3.                                                 mordenite                                                                           400 14.2                                                                             100.0                                                                             14.2                                           5.4 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      78   6.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  mordenite                                                                           425 22.3                                                                             99.0                                                                              22.1                                           5.4 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      79   6.5 · 10.sup.-2.Al.sub.2 O.sub.3.                                                  mordenite                                                                           450 32.4                                                                             86.4                                                                              26.2                                           5.4 · 10.sup.-4.Fe.sub.2 O.sub.3.SiO.sub.2                      80   5.0 · 10.sup.-5.Na.sub.2 O.                                                        ZSM-23                                                                              350 14.5                                                                             100.0                                                                             14.5                                           1.2 · 10.sup.-2.Al.sub.2 O.sub.3.                                    1.1 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      81   3.1 · 10.sup.-4.Na.sub.2 O.                                                        BETA  350  9.8                                                                             99.0                                                                               9.7                                           6.0 · 10.sup.-2.Al.sub.2 O.sub.3.                                    1.2 · 10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                      82   6.1 · 10.sup.-4.Na.sub.2 O.                                                        EU-1  350 15.0                                                                             98.0                                                                              14.5                                           10.sup.-2.Al.sub.2 O.sub.3.1.4 ·                                     10.sup.-3.Fe.sub.2 O.sub.3.SiO.sub.2                                     __________________________________________________________________________

EXAMPLE 86

Phenol was prepared as in Example 1 hereinbefore, except that use wasmade of a catalyst having the composition of 8.4.10⁻³.Fe₂ O₃.SiO₂containing, as the binder, 29% by mass of Al₂ O₃ and 70% by mass ofSiO₂, and the process was conducted at the temperature of 450° C. Theprocess had the following parameters:

    ______________________________________                                        conversion of benzene, X                                                                         9.5%                                                       selectivity for phenol, S                                                                        98.0%                                                      yield of phenol, Y 9.3%                                                       ______________________________________                                    

EXAMPLE 87

A synthetic zeolite of the composition of 1.10.10⁻⁴.Na₂ O. 1.10⁻⁴. Al₂O₃.8.4.10⁻³.Fe₂ O₃.SiO₂ with the structure of ZSM-5 in the amount of 2cm³ was charged into a reactor, heated to the temperature of 350° C. anda reaction mixture of the composition: 5 mol. % benzene, 20 mol. %nitrous oxide, the balance, helium, was fed thereinto at the rate of 1cm³ /sec. After the reactor the mixture composition was discontinuously(once every 15 minutes) analyzed by means of a chromatograph. Along withphenol there were formed: benzoquinone, diphenylmethane, cresol anddibenzofuran. The process parameters were the following:

    ______________________________________                                        conversion of benzene                                                                             47.6%                                                     selectivity for phenol                                                                            78.7%                                                     selectivity for benzoquinone                                                                       7.2%                                                     ______________________________________                                    

    ______________________________________                                        selectivity for diphenylmethane                                                                    8.0%                                                     selectivity for dibenzofuran                                                                       0.2%.                                                    ______________________________________                                    

The total yield of the products of partial oxidation was equal to 45.2%.

EXAMPLE 88

A zeolite of the composition of 5.10⁻³.P₂ O₅.4.10⁻⁴. Al₂ O₃ 10⁻².Fe₂O₃.SiO₂ with the structure of ZSM-5 was charged into a reactor in theamount of 2 cm³, heated to the temperature of 350° C. and a reactionmixture of the composition: 2 mol. % phenol, 20 mol. % nitrous oxide,the balance, helium, was fed into the reactor at the rate of 1 cm³ /sec.The mixture composition after the reactor was analyzed by means of achromatograph. The main products of the reaction were pyrocatechol andbenzoquinone. The process had the following parameters:

    ______________________________________                                        conversion of phenol                                                                               8.0%                                                     selectivity for pyrocatechol                                                                      77.8%                                                     selectivity for benzoquinone                                                                      16.4%                                                     total yield of the products                                                                        7.5%                                                     of partial oxidation                                                          ______________________________________                                    

EXAMPLE 89

Pyrocatechol and benzoquinone were prepared in a manner similar to thatdescribed in Example 88, except that the charge of the catalyst wasincreased to 4 cm³. The process parameters were the following:

    ______________________________________                                        conversion of phenol                                                                              11.5%                                                     selectivity for pyrocatechol                                                                      76.0%                                                     selectivity for benzoquinone                                                                      16.0%                                                     total yield of the products                                                                       10.7%                                                     of partial oxidation                                                          ______________________________________                                    

EXAMPLE 90

A zeolite of the composition: 10⁻².Al₂ O₃.2.8.10⁻⁴.Fe₂ O₃ .SiO₂ with thestructure ZSM-5 in the amount of 4 cm³ was charged into a reactor,heated to the temperature of 375° C. and a reaction mixture: 2 mol. %phenol, 20 mol. % nitrous oxide, the balance, helium, was fed thereintoat the rate of 1 cm³ /sec. The mixture composition after the reactor wasdiscontinuously (once every 15 minutes) analyzed by means of achromatograph. The main products of the reaction were pyrocatechol andhydroquinone. The process parameters averaged for 3 hours of operationwere the following:

    ______________________________________                                        conversion of phenol                                                                              15.1%                                                     selectivity for hydroquinone                                                                      39.8%                                                     selectivity for pyrocatechol                                                                      22.6%                                                     total yield of the products                                                                        9.4%                                                     of partial oxidation                                                          ______________________________________                                    

EXAMPLE 91

A zeolite of the composition of 8.2.10⁻³.Fe₂ O₃.SiO₂ with a structure ofthe ZSM-5 type was charged into a reactor in the amount of 2 cm³, heatedto the temperature of 350° C. and a reaction mixture of the composition:5 mol. % chlorobenzene, 20 mol. % nitrous oxide, the balance, helium,was fed thereinto at the rate of 1 cm³ /sec. The mixture compositionafter the reactor was discontinuously (once every 15 minutes) analyzedby means of a chromatograph. The main products of the reaction werechlorophenols. The process parameters averaged for three hours ofoperation were the following:

    ______________________________________                                        conversion of chlorobenzene                                                                        17.0%                                                    selectivity for para-chlorphenol                                                                   39.0%                                                    selectivity for ortho-chlorophenol                                                                 60.0%                                                    total yield of chlorophenol                                                                        16.8%                                                    ______________________________________                                    

EXAMPLE 92

A zeolite of the composition of 8.4.10⁻³.Fe₂ O₃.SiO₂ with a structure ofthe ZSM-5 type was charged into a reactor in the amount of 2 cm³ and areaction mixture of the composition: 5 mol. % toluene, 20 mol. %nitrogen oxide, the balance, helium, was fed into the reactor at therate of 1 cm³ /sec. The mixture composition after the reactor wasanalyzed by means of a chromatograph. The main products of the reactionof oxidation were cresols (nearly equal amounts of ortho-, para- andmeta-isomers) and diphenylethane (product of oxidizing dimerization oftoluene). The process parameters were the following:

    ______________________________________                                        conversion of toluene                                                                            48.1%                                                      total selectivity for cresols                                                                    20.3%                                                      selectivity for phenol                                                                            1.8%                                                      yield of oxygen-containing                                                                        10.6%.                                                    benzene derivatives                                                           ______________________________________                                    

We claim:
 1. A process for preparing phenol or derivatives thereof comprising oxidation of the aromatic nucleus of benzene or derivatives thereof with nitrous oxide at a temperature within the range of 275° C. to 450° C., in the presence of a zeolite catalyst of the composition: y.El₂ O_(n).x.Fe₂ O₃.SiO₂, wherein y=0-6.5. 10⁻², x=1.5.10⁻⁵ -2.10⁻², El at least one element of Periods 2, 3, 4 and 5 of the periodic system; n is valence of the element El and at a time of contact of the reaction mixture with the catalyst of not more than 8 seconds.
 2. A process according to claim 1 wherein the zeolite catalyst has a structure analogous to ZSM-5, ZSM-11, ZSM-12, mordenite, BETA and/or EU.
 3. A process according to claim 1 wherein phenol is produced from benzene.
 4. A process according to claim 1 wherein phenol and benzoquinone are produced from benzene.
 5. A process according to claim 1 wherein dihydric phenols are produced from phenol.
 6. A process according to claim 1 wherein dihydric phenols and benzoquinone are produced from phenol.
 7. A process according to claim 1 wherein halogen-containing phenols are produced from halogen-containing benzene.
 8. A process according to claim 1 wherein cresols are produced from toluene.
 9. A process according to claim 1 wherein said catalyst is used in combination with a binder employed in an amount of from 1.0% to 99.0% by mass.
 10. A process according to claim 9, wherein the binder is alumina and/or silica.
 11. A process according to claim 1 wherein the process is conducted in the presence of an inert gas. 